County annual report · FIPS 46025
2020 Clark County, SD Power Outage Report
In 2020, customers in Clark County, SD went without power for an average of 12.1 hours, a total of 19K customer-hours (South Dakota average 4.6 hours). That ranks 6th worst of 62 South Dakota counties and 662nd of 3,019 nationally.
Compared with SD, the US and 2019
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Clark County, 2020
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | June 5, 2020 01:30 | June 5, 2020 05:30 | 4h | 563 | 917 |
| 2 | December 9, 2020 18:30 | December 9, 2020 23:00 | 4h 30m | 427 | 571 |
| 3 | June 13, 2020 01:00 | June 13, 2020 03:00 | 2h | 365 | 366 |
| 4 | August 28, 2020 07:15 | August 31, 2020 12:30 | 3d 5h | 267 | 533 |
| 5 | October 7, 2020 14:45 | October 7, 2020 16:15 | 1h 30m | 204 | 306 |
| 6 | July 9, 2020 03:45 | July 15, 2020 17:45 | 6d 14h | 153 | 12K |
| 7 | August 8, 2020 17:45 | August 8, 2020 22:00 | 4h 15m | 77 | 316 |
| 8 | April 22, 2020 15:15 | April 22, 2020 18:15 | 3h | 63 | 67 |
| 9 | June 7, 2020 23:00 | June 10, 2020 21:15 | 2d 22h | 55 | 3,525 |
| 10 | June 15, 2020 08:30 | June 15, 2020 20:30 | 12h | 38 | 225 |
Outage episodes by size in 2020: 6 reached 100+ customers, 0 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Clark County reported on EIA Form 861 for 2020, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| NorthWestern Energy - (SD) | 2020 | 2.6 hrs | 1.54 | 1.9 hrs | 1.28 |
| Northern Electric Coop, Inc | 2020 | 1.7 hrs | 0.62 | 1.6 hrs | 0.56 |
| H-D Electric Coop Inc | 2018 | 2.6 hrs | 1.52 | 1.6 hrs | 1.14 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Codington-Clark Elec Coop, Inc | - | - | - | - | - |
| Kingsbury Electric Coop, Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 79% of South Dakota's customers in 2020; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 1,587 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Clark County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Clark County, SD annual power outage report, 2020, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2020/south-dakota/clark-county